Pipe threading device



June 14, 1932.

C. B. PERRY PIPE THREADING DEVICE Filed April 4, 1928 ATTORNEY Patented June 14, 1932 UNETED STATES PATENT QF' EQE CLAUDE B. PERRY, OF SAN JOSE, CALIFORNIA PIPE THREAJJING DEVICE Application filed April 4, 1928. Serial No. 267,161.

The invention forming the subject matter considered to be the best, but it is to be unof this application relates to pipe threading derstood that the invention is not limited devices using inside guides. to such form because it may be embodied in The standard threading device or cutter other form; and it is also to be understood used at present supports the cutter at a rethat in and by the claims following the demote point and not opposite the point where scription, it is desired to cover the invention the dies are pressed against the pipe to be in whatsoever form it may be embodied. threaded. The tool support is usually sev- The invention is clearly illustrated in the eral inches from the cutter itself. At present accompanying drawing in which,

19 it is necessary to use an outside bushing Figure 1 is a front view of the pipe threadwhich forms part of the casting of the threading device as attached to a standard tool, ing tool, thus elongating the tool. Further- Figure 2 is a sectional view of the device, more, the bushing on the tool forming the the section being taken along the line 22 outside guide on the pipe also spaces the of Figure 1,

15 dies from the vise, thus preventing the cut- Figure 3 is a sleeve of larger outside diam- 55 ting of the thread on the pipe up to the vise eter than that in Figure 4 and used for the holding the same. In case the threading same purpose, device or cutter is used for cutting thread on Figure 4 is a sleeve to be used in conjuncshort nipples, the aforementioned bushing tion with the inside guide of my device for go obstructs the movement of the cutting tool adapting the guide to be used in connection on the portion of the nipple'adjacent to the with pipes of various inside diameter, vise in which it is held. Figure 5 is a cross-sectional view of my The primary object of the invention is to device used in conjunction with a ratchetless provide a threading device or thread cutter thread cutting device, the type commonly 2.3 in Which a guide is provided for supporting described in the trade as Armstrong pipe 7 the device at a point opposite the cutting tool, thr d tti g d vi said guide being adapted to be disposed and R ferring to the accompanying drawing moved inside Of the pipe. wherein similar reference characters desig- Another object of the invention is the p nate similar parts throughout, the various '30 vision of a pipe threading device Which iS figures described above adequately illustrate guided by a support movable insi e f the my invention, and the following detailed pipe and in which the use of an outside guide d i ti i Commensurate ith th above is en irely limin d S0 as to Permit the mentioned drawing in enabling an artisan to constructi n of a compact and Sh rt i001 construct and assemble the constituent parts :35 adapted to cut thread up to the portion of a f th a pipe adjacent to the vise holding the same. In carrying out my invention, I employ a A still further object of the invention is stock frame 6, in which are inserted dies 7 the provisi n O a pip threading device forming a desired male thread, when rotated which uses the inside instead of the outside d th ded n a pip 8. The frame 6 has -10 periphery of the pipe for guiding and sup a long handle 9 radially extending therefrom porting the thread cutting tool while out by means f which the tool is rotated. Aling he hre though the handle 9 may be directly con- Other objects of the invention are to pr0 nected to a frame, in the illustration shown vide a device of the character decribed that in Figures 1 and 2, the handle 9 is operatively will be superior in point of simplicity, ineX- connected to the stock frame 6 by means of pensiveness of construction, positiveness of a ratchet ring 11 into which the handle 9 eX- operation, and facility and convenience in tends. Aspring pawl denoted by the numeral use and general eificiency. 12, not shown in detail, engages the recess 13 In this specification and the anneXeCl draW- of the outside periphery of the frame when 59 ing the invention is illustrated in the form the handle 9 is moved in one direction. The

spring pawl is usually reversible, so as to be used also when the stock is removed after the thread is cut.

face of the die retaining. ring 16. On the studs is supported a spider 19 which spider is readily secured in place by the tightening of nuts 21 on the studs 18. In order to obviate the necessity of the removal of the nuts 21 when the spider is to be detached from the die retaining ring, the arms of the spider are provided with slots 22, all the slots pointing in the same direction of rotation so that when the nuts 21 are loosened then the spider 19 may be readily removed by rotating the same slightly in a counter clockwise direction, looking at Figure 1, thus disengaging the slots 22 from the studs 18 and permitting the ends of the spider arms to clear the nuts 21. An inside guide spindle 23 is secured into the'hub portion 2 1 of the spider 19 by means of a nut 25 threadedly engaging a reduced end 26 of the guide spindle 23. The guide spindle 23 extends beyond the rear wall 14 of the stock frame 6 and is of'suoh diameter as to slidably fit the inside of a pipe on which the thread is to be cut.

It is to be noted that there is no bushing provided on the outside of the stock frame 6 for supporting and guiding the same on the outside periphery of the pipe 8, because the thread cutting device is supported wholly by the guide spindle 23 on the inside periphery of the pipe 8. It is also to be noted that the inside guide spindle 23 also supports the thread cutting device at a point directly inside and opposite to the dies 7.

The cutting of the thread may be readily accomplished by inserting the guide spindle 23 in the pipe 8 and advancing the die until the same is in cutting relation with the end of the pipe 8 then by turning the stock frame 6, the dies 7 are rotated therewith and thus threaded on the pipe in the usual manner. The guide spindle 23 advances inside of the pipe with the advancement of the dies 7 while the latter cuts the thread. The cutting device may be also employed for cutting a running thread as it is frequently used on electric conduits. In, such a case, the inside guide can be readily removed by loosening the nut 21 and removing the spider 19 and the guides 23 therewith in the manner heretofore described. It is to be observed that the spider may be readilyremoved without in any way changing the position of the die retaining ring 16 relative to the die 7. Thus the spindles may be readily replaced by spindles fitting the inside of extra heavy and double this case the same stock frame is used for several sizes of thread cutting dies. The guide spindle 23 is of such diameter as to conform to the inside diameter of the smallest pipe on which a thread may be cut by the particular tool.

When the dies 7 are exchanged in the usual manner for a larger size so as to cut threads on a larger pipe, then the increase ofthe diameter of the sliding guide 23 is effected by means of a sleeve 27 of such diameter as to conform to the increase of the size of the dies 7. The sleeve 27 is provided with an annular groove 28 near to the end thereof adjacent to the spider 19, the other end of the sleeve being slightly tapered so as to facilitate the insertion of the sleeve into the pipe 8. In some cases, the friction developed between the sleeve 27 and the inside periphery of the pipe 8 may tend to retain the sleeve when the tool is withdrawn from the pipe and cause the sleeve to slide 01f the guide spindle 23. Therefore, a set screw 29 isthreadedly secured in the die retaining ring at a distance from the spider 19 and opposite to the annular groove 28. Normally, the set screw 29 is in about the position shown in Figure 2, but when the sleeve 27 is slid upon the guide spindle 23, the set screw 29 is advanced so as to engage said annular groove 28, thereby preventing the accidental displacement or removal of the sleeve 27 from the guide spindle 23. In case the dies 7 are replaced with still larger dies, then a thicker sleeve 31 is' slid upon the guide spindle 23. The design of the sleeve 31 is similar to that of the sleeve 27 excepting that the inside diameter thereof is increased at the central portion of the sleeve, thus reducing the weight andthe bulk of the sleeve. A sleeve is provided for each size of pipe within the range of a particular thread-cutting device.

In Figure 5 is shown the adaptation of my inside guide spindle principle to a threading device of the type having two oppositely disposed handles 9a thereon directly secured to a ratchetless stock frame 32.' In this type of thread-cutting device, the dies are not secured in place by means of die retaining rings, but are directly secured to the stockcasing by means of screws or bolts.

My improvement on this device involves the extending of the stock casing 32 soas to form an annular hub 33 upon which is disposed the spider 19 and guide spindle 23,

eretofore described. Figure 5 shows the adaptation of the standard so-called Armstrong type of threading device so as to permit the employment of the set screw 29 for retaining the sleeve 27 upon the guide spindle 23 and also for receiving the studs 18 upon which the spider 19 is supported.

It will be recognized that a particularly facile device is provided to accomplish the above described guiding of a thread cutting device by means of a spindle inside of a pipe; and which combines light Weight and ready adaptation for different sizes and types of thread cutting devices, with a ruggedness of construction and positiveness of operation especially adapting it for its use. Being a unitary character the device requires no careful setting up and lends itself to effective application by the labor ordinarily available.

Having thus described my invention, what I now claim as novel and desire to secure by Letters Patent is:

1. A pipe threading device comprising, in combination with a die, a die stock provided with a cylindrical axial extension relative to said die, a spider consisting of a central hub and a plurality of radial arms, concentric slots adjacent the ends of said arms adapted to cooperate with studs, a plurality of studs secured in said extension, a pilot secured in said hub and extending through said die, a sleeve rotatable on said pilot, and means retaining said sleeve against withdrawal on said pilot.

2. In combination with a die stock provided with a central pilot, a sleeve rotatably mounted on said pilot, an annular groove in said sleeve and a screw secured in said stock and cooperating with said annular groove.

In testimony whereof I afiix my signature.

CLAUDE B. PERRY. 

